Police are appealing for witnesses to the collision, which happened around 6pm yesterday.
They say a red Vauxhall Astra was travelling from Fakenham towards Wells when it collided with a telegraph pole and ended up in a ditch.
The driver and front seat passenger received serious internal injuries and are in what is described as a 'critical but stable condition' in Addenbrookes Hospital.
Witnesses should call PC Louise Manning on 101, at Swaffham roads policing, on 101.
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